Dishwasher having Spray Manifold

ABSTRACT

A dishwasher includes a tub at least partially forming a treating chamber, a dish rack provided within the wash chamber, and a spray manifold. The spray manifold can have multiple apertures and/or sprayers for emitting wash liquid to define a spray zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 14/807,928,filed Jul. 24, 2015, which is a division of U.S. application Ser. No.13/274,414, filed Oct. 17, 2011, which issued as U.S. Pat. No. 9,119,517on Sep. 1, 2015, all of which are incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a dishwasher and more particularly to adishwasher having multiple wash zones including an intensified wash zonefor cleaning heavily soiled dishes.

Background

Modern dishwashers include a tub and an upper and lower rack or basketfor supporting soiled dishes within the tub. A pump is provided forre-circulating wash liquid throughout the tub to remove soils from thedishes. Typically, larger dishes such as casserole dishes which have apropensity to be heavily soiled are carried on the lower rack andlighter soiled dishes such as cups and glasses are provided on an upperrack. The racks are generally configured to be moveable in or out of thetub for loading and unloading.

One of the problems associated with the typical modern dishwasher isthat the dishes receive somewhat uniform wash treatment no matter theirpositioning within a rack in the dishwasher. For example, in a typicaldishwasher, a lower wash arm rotates about a vertical axis and isprovided beneath the lower rack for cleaning the dishes on the lowerrack and an upper wash arm is provided beneath the upper rack forcleaning the dishes on the upper rack. Dishes in the upper rack receivesomewhat uniform wash treatment and dishes in the lower rack receivesomewhat uniform wash treatment. Accordingly, lightly soiled dishes ineither dish rack are subject to the same wash performance as the highlysoiled dishes in the same wash rack, which can lead to poor washperformance of the highly soiled dishes. As a result, it would beadvantageous to provide a dishwasher with a second or concentrated washzone for washing larger dishes such as the casserole dishes, which aremore likely to be heavily soiled.

Another problem associated with the modern dishwasher is that to achieveoptimal wash performance of heavily soiled, larger dishes, the dishesmay need to be loaded with the surface that needs to be washed facedown. The face down approach allows the lower spray arm to reach theheavily soiled surface. Accordingly, it would be advantageous if thedishwasher could be provided with a second wash zone that allowed theheavily soiled dishes to be loaded in an upright position, therebyoptimizing the number of dishes that can be loaded in the dishwasher onany given cycle. Finally, it would also be advantageous if thedishwasher allowed for a customized wash cycle option which optimizedthe use of the second wash zone.

SUMMARY OF THE INVENTION

The invention relates to a dishwasher having a tub at least partiallyforming a treating chamber, a dish rack provided within the washchamber, and a spray manifold.

In one aspect of the invention, the spray manifold has multipleapertures, multiple branches, a liquid distribution header defining aninterior flow path having an inlet from which extends multiple channelscorresponding to the multiple branches, with each of the channels influid communication with the corresponding branch, and a supply conduitin fluid communication with the inlet for supplying wash liquid to theliquid distribution header, wherein the corresponding channel and branchhave matching volumetric flow rate requirements to minimize pressureloss from the inlet to the branches.

In another aspect of the invention, the spray manifold has first andsecond rotating spray heads, and first and second interior flow pathsthat supply liquid to the rotating spray heads, wherein the first andsecond interior flow paths are configured to supply liquid to the firstand second rotating spray heads, respectively, at the same volumetricflow rate.

In yet another aspect of the invention, the spray manifold has multiplerotating spray heads, each spray head having at least one aperture, andmultiple liquid flow paths, each flow path corresponding to a rotatingspray head, with each flow path supplying liquid at the same volumetricflow rate to the corresponding rotating spray head.

Still other aspects of the present invention will become apparent tothose skilled in the art from the following detailed description, whichis simply by way of illustration several of the best modes contemplatedfor carrying out the invention. As will be realized, the invention iscapable of other different obvious aspects, all without departing fromthe invention. Accordingly, the drawings and descriptions areillustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, incorporated in and forming part of thespecification, illustrate several aspects of the present invention andtogether with their description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a perspective view of a dishwasher having multiple wash zonesin accordance with a first embodiment of the present invention;

FIG. 2 is a schematic, cross-sectional view of the dishwasher shown inFIG. 1, showing the dish racks mounted in the tub, upper and lower sprayarm assemblies and a spray manifold as contemplated by the presentinvention;

FIG. 3 is a front elevational view of a spray manifold in accordancewith the first embodiment of the present invention;

FIG. 4A is a schematic view of a first position of a valve forselectively diverting wash liquid to a supply tube in accordance withthe first embodiment of the present invention;

FIG. 4B is a schematic view of a second position of a valve forselectively diverting wash liquid to a spray manifold in accordance withthe first embodiment of the present invention;

FIG. 5 is a schematic view of the valve and actuator in accordance withthe first embodiment of the present invention;

FIG. 6 is a perspective view of a dishwasher having a spray manifold inaccordance with a second embodiment of the present invention;

FIG. 7 is a schematic, cross-sectional view of the dishwasher shown inFIG. 6;

FIG. 7A is a schematic illustration of a liquid supply system of thedishwasher 10;

FIG. 8 is a front perspective view of the spray manifold from FIG. 6;

FIG. 9 is a rear perspective view of the spray manifold from FIG. 6;

FIG. 10 is a front perspective view of the spray manifold from FIG. 6,with a portion of the spray manifold cut away to illustrate the liquidflow paths through the spray manifold;

FIG. 11 is a top view of a portion of FIG. 10, illustrating a flowdivider provided in the spray manifold;

FIGS. 12 and 13 are schematic front and side views of the spray manifoldfrom FIG. 6, illustrating the spray pattern of wash liquid from thespray manifold;

FIG. 14 is a perspective view of a dishwasher having a spray manifold inaccordance with a third embodiment of the present invention;

FIG. 15 is a schematic, cross-sectional view of the dishwasher shown inFIG. 13;

FIG. 16 is a front perspective view of the spray manifold from FIG. 13;

FIG. 17 is a rear perspective view of the spray manifold from FIG. 13;

FIG. 18 is an exploded view of a portion of the spray manifold from FIG.13, illustrating the components of a rotating sprayer of the spraymanifold;

FIG. 19 is a rear view of a cap for the rotating sprayer shown in FIG.18;

FIG. 20 is a front perspective view of the spray manifold from FIG. 14,with a portion of the spray manifold cut away to illustrate the liquidflow paths through the spray manifold;

FIG. 21 is a rear perspective view of a portion of the spray manifoldfrom FIG. 14, with a portion of the spray manifold cut away toillustrate the liquid flow paths through the spray manifold; and

FIG. 22 is a top view of a portion of FIG. 20, illustrating a flowdivider provided in the spray manifold.

DETAILED DESCRIPTION

Referring now to the drawings in detail, wherein like numerals indicatethe same elements throughout the views, FIGS. 1 and 2 illustrate anexemplary embodiment of a multiple wash zone dishwasher 10 in accordancewith the present invention. In the embodiment shown generally in FIGS. 1and 2, the dishwasher generally designated as 10 includes an interiortub 12 having a top wall 13, bottom wall 14, two side walls 15 and 16, afront wall 17 and a rear wall 18, which form an interior wash chamber ordishwashing space 19 for washing dishes. As one of skill in the art willappreciate, the front wall 17 may be the interior of door 20, which maybe pivotally attached to the dishwasher for providing accessibility tothe dishwashing space 19 for loading and unloading dishes or otherwashable items. While the present invention is described in terms of aconventional dishwashing unit as illustrated in FIG. 1, it could also beimplemented in other types of dishwashing units such as in-sinkdishwashers or drawer dishwashers.

The bottom wall 14 of the dishwasher may be sloped to define a lower tubregion or sump 11 of the tub 12. A pump assembly 21 may be located in oraround a portion of the bottom wall 14 and in fluid communication withthe sump 11 to draw wash liquid from the sump 11 and to pump the liquidto at least a lower spray arm assembly 22. If the dishwasher has amid-level spray arm assembly 23 and/or an upper spray arm assembly 24,liquid may be selectively pumped through a supply tube 25 to each of theassemblies for selective washing. As shown in FIG. 2, the supply tube 25extends generally rearwardly from the pump assembly 21 to the rear wall18 of the tub 12 and extends upwardly to supply wash liquid to either orboth of the mid-level and upper spray arm assemblies 23, 24.

In the exemplary embodiment, the lower spray arm assembly 22 ispositioned beneath a lower dish rack 26, the mid-level spray armassembly 23 is positioned between an upper dish rack 27 and the lowerdish rack 26, and the upper spray arm assembly 24 is positioned abovethe upper dish rack 27. As is typical in a conventional dishwasher, thelower spray arm assembly 22 is configured to rotate in the tub 12 andspray a flow of wash liquid, in a generally upward direction, over aportion of the interior of the tub 12. The spray from the lower sprayarm assembly 22 is typically directed to providing wash liquid fordishes located in the lower dish rack 26. Like the lower spray armassembly 22, the mid-level spray arm assembly 23 may also be configuredto rotate in the dishwasher 10 and spray a flow of wash liquid, in agenerally upward direction, over a portion of the interior of the tub12. In this case, the spray from the mid-level spray arm assembly 23 isdirected to dishes in the upper dish rack 27. Typically, the upper sprayarm assembly 24 generally directs a spray of wash liquid in a generallydownward direction and helps wash dishes on both the upper and lowerdish racks 26, 27. The spray of wash liquid from any one of these sprayarm assemblies 22, 23, 24 or from all three in combination is consideredto define a first utensil or “wash zone” 50.

In addition to one or more of the conventional spray arm wash assemblies22, 23, 24 described above, the present invention further comprises asecond utensil or “wash zone”, or more particularly, an intensified washzone 28. While in the exemplary embodiment, the second wash zone 28 islocated adjacent the lower dish rack 27 toward the rear of the tub 12,it could be located at virtually any location within the interior tub12. The second wash zone 28 has been designed to allow heavily soileddishes such as casserole dishes to receive the traditional spray armwash, as well as, an additional concentrated wash action. Thus, adishwasher having such a zone may not only provide better washingperformance for heavily soiled dishware, but may provide overallimproved wash performance.

As illustrated in FIG. 3, the second wash zone 28 is achieved byselectively diverting wash liquid from the mid-level and upper spray armassemblies 23, 24 to a vertically oriented spray manifold 29 positionedon the rear wall 18 of the interior tub 12 adjacent the lower dish rack26. In this way, a flow of wash liquid is directed toward the lower dishrack 26 from the manifold 29 thereby providing the second wash zone 28.As one of skill in the art should recognize, the spray manifold 29 isnot limited to this position, rather, the spray manifold 29 could belocated in virtually any part of the interior tub 12. For example, themanifold 29 could be moved up vertically along any portion of the washliquid supply tube 25 such as to a position adjacent the upper dish rack27. Alternatively, the manifold 29 could be positioned underneath thelower dish rack 26 adjacent or beneath the lower spray arm assembly 22.The current positioning of the spray manifold 29 was chosen to allow forcasserole dishes to be loaded in an upright position, which helpsmaximize or optimize the amount of dishware that can be loaded in anygiven cycle.

In the exemplary embodiment, the spray manifold 29 is in fluidcommunication with the wash liquid supply tube 25 such that wash liquidmay be selectively provided to the manifold 29. The manifold 29 isconfigured to have two symmetrically opposing halves 31, 32 positionedon opposite sides of the supply tube 25 with each half being configuredto selectively receive wash liquid being pumped through the supply tube25. Each half 31, 32 of the manifold 29 comprises a plurality ofapertures 30 configured to spray wash liquid into the wash zone 28.Additionally, each half of the manifold is configured with one or morepassageways 33 to deliver wash liquid from the supply tube 25 to theapertures 30. As one of skill in the art will appreciate, the washliquid being pumped through the supply tube 25 will be under pressure asit passes through passageway 33 and out apertures 30, thereby creatingan intensified wash zone 28.

As illustrated in FIG. 3, it is contemplated that each half 31, 32 ofthe spray manifold may comprise two substantially circular nozzles 34,35 having a plurality of apertures 30 arranged in a substantiallycircular pattern. Each aperture 30 may be a substantially oval shape andmay be provided at any angle with respect to the nozzle or with respectto the spray manifold 29. While the exemplary embodiment of theinvention is illustrated in FIG. 3, the present invention is not meantto be limited by this illustration. For example, the spray manifold 29may extend across virtually any width of the interior wash tub, or maybe limited to extending to only one side of the supply tube 25.Moreover, the number of nozzles 34, 35 may vary, as well as the heightand positioning of each nozzle. Additionally, the shape, size, angle,arrangement and number of apertures 30 in the manifold 29 may vary asalternative arrangements may provide a more concentrated wash zone. Forexample, not only can the manifold be configured to provide water flowto a particular area, but the water flow from the manifold may also beconfigured to have more speed or more volume per area.

As shown generally in FIG. 3 and more specifically in FIGS. 4A and 4B, avalve 40 may be provided to selectively divert wash liquid from themid-level and upper spray arm assemblies 23, 24 to the spray manifold29. In the exemplary embodiment, the valve 40 is a magneticallyactuatable diverter valve positioned in the supply tube 25 and isconfigured to direct the flow of wash liquid either through the supplytube 25 so it can reach the mid-level and upper spray arm assemblies 23,24 or through the spray manifold 29 so it can reach the intensified washzone 28. As one of skill in the art should appreciate, the valve 40could also be designed to selectively divert water from the lower sprayarm 22.

In the exemplary embodiment, the valve 40 comprises a housing 43 and twodiverter objects such as magnetic balls 41, 42 preferably having aferrite core positioned within the housing and configured to bemagnetically moved between a first position shown in FIG. 4A and asecond position shown in FIG. 4B. In the first position, the diverterobjects 41, 42 are magnetically positioned to substantially blockpassageway 33 associated with both halves 31, 32 of the spray manifold29. In this way, wash liquid is prevented from entering the manifold 29and is pushed through the supply tube 25 toward the mid-level and upperspray arm assemblies 23, 24. In the second position, the diverterobjects 41, 42 are magnetically positioned to substantially block thesupply tube 25, thereby allowing the wash liquid to enter both halves31, 32 of the manifold 29 through passageway 33. While the exemplaryembodiment contemplates that the diverter valve 40 may use a pluralityof magnetic objects such as magnetic balls to divert wash liquid betweenthe mid-level and upper spray arm assemblies 23, 24 and the manifold 29,one of skill in the art will recognize that an arrangement of flappervalves, wedges, or other known water diverter mechanisms could be alsobe used.

As shown in FIG. 5, an actuator 44 is positioned outside of the housing43 and behind the tub 12 for magnetically moving the objects 41, 42 fromthe first position to the second position and vice versa. In theexemplary embodiment, the actuator 44 comprises a magnet with sufficientstrength to magnetically manipulate the diverter objects 41, 42. Itshould be recognized that the magnet could be a permanent magnet,electromagnet or any other type magnet configured to move the diverterobjects 41, 42. The actuator 44 can be configured to be mounted to theoutside 46 of the tub 12 in any variety of ways and can be configured tobe in communication with and controlled by the dishwasher's controlpanel (not shown) or the wash programs associated with the dishwasher10. It should be recognized that to take advantage of the second washzone 28, the dishwasher 10 might be configured with customized washcycle options that provide for zone actuation at optimal cycleintervals.

FIG. 6 is a perspective view of a dishwasher 10 having a spray manifold52 in accordance with a second embodiment of the present invention. Thedishwasher 10 can be substantially similar to the dishwasher 10 shown inFIG. 1, with the exception that the spray manifold 52 is employed inplace of the spray manifold 29.

The spray manifold 52 comprises multiple sprayers 54 through whichliquid is sprayed into the wash chamber 19. The sprayers 54 are fluidlycoupled to a common liquid distribution header 56. A supply conduit 58supplies liquid to the spray manifold 52 from a liquid source and isfluidly coupled to the liquid distribution header 56. A bracket 60positioned between the sprayers 54 is used to couple the spray manifold52 to the tub 12, and can extend around the supply tube 25 to secure thespray manifold 52 to the rear wall 18 of the tub 12. The sprayers 54,liquid distribution header 56, supply conduit 58, and bracket 60 can beintegrally formed together as a single molded piece. Alternatively, oneor more of the components of the spray manifold 52 can be formedseparately and physically coupled together, using suitable sealing meansas needed to create a fluid-tight spray manifold 52.

FIG. 7 is a schematic, cross-sectional view of the dishwasher 10 shownin FIG. 6. The spray manifold 52 can be positioned adjacent the rearwall 18 of the interior tub 12 adjacent the lower dish rack 26. In thisway, a flow of wash liquid is directed toward the lower dish rack 26from the manifold thereby providing a second utensil or wash zone 62.Like the first embodiment, the first wash zone 50 is provided by thespray of wash liquid from any one or combination of the spray armassemblies 22, 23, 24. The spray manifold 52 can extend in a generallyhorizontal manner across a partial width of the lower dish rack 26.However, the spray manifold 52 may extend across virtually any width ofthe rack 26 or tub 12. Furthermore, one or more of the multiple sprayers54 can extend above an upper edge 63 of the lower dish rack 26 such thatthe sprayers 54 not only spray through the side of the lower dish rack26, but also across the top of the lower dish rack 26. The position ofthe spray manifold 52 shown, particularly the sprayers 54 extending bothbelow and above the upper edge 63 of the lower dish rack 26, allows forcasserole dishes or 9″×13″ pans to be loaded into the lower dish rack 26in an upright position, which helps maximize or optimize amount ofdishware that can be loaded in any given cycle while still effectivelycleaning the casserole dish or 9″×13″ pan.

The spray manifold 52 can include at least one spacer 76 that provides agap between the rear side of the spray manifold 52 and the rear wall 18of the tub 12. As shown, multiple spacers 76 are provided on the spraymanifold 52. The gap created by the spacers 76 permits some wash liquidto flow between the spray manifold 52 and the tub 12, which rinses soilout of the gap and prevents the accumulation of soil behind the spraymanifold 52.

FIG. 7A is a schematic illustration of a liquid supply system of thedishwasher 10. In the second embodiment, the spray manifold 52 isconfigured to receive liquid from the supply conduit 58. Therefore,rather than being in fluid communication with the supply tube 25 thatprovides liquid to either or both of the mid-level and upper spray armassemblies 23, 24, as in the first embodiment, the spray manifold 52receives liquid via the separate and dedicated supply conduit 58 thatextends along the bottom wall of the tub 12 to the liquid distributionheader 56.

A suitable valve mechanism 350 can be provided such that only one of thesupply tube 25 and supply conduit 58 can receive liquid at one time.Such a valve mechanism 350 is set forth in detail in U.S. patentapplication Ser. No. 12/908,915, filed Oct. 21, 2010, now U.S. Pat. No.8,834,648, issued Sep. 16, 2014, and titled “Dishwasher with ControlledRotation of Lower Spray Arm,” which is incorporated herein by referencein its entirety. The valve mechanism 350 can comprise a diverter valvethat includes a diverter disk 352 having at least one port 354 forselectively liquid to the supply tube 25 or the supply conduit 58 andthat rotates relative to a diverter base 356 having at least two fluidpassages. As shown herein, the diverter base 356 includes a firstpassage 358 in fluid communication with the supply tube 25, a secondpassage 360 in fluid communication with the supply conduit 58, and athird passage 362 in fluid communication with the lower spray armassembly 22. The diverter disk 352 can be operably coupled with a driveshaft 364 of a motor 366 and is rotated as the motor 366 drives thedrive shaft 364.

The valve mechanism 350 can be supplied with liquid from the sump 11 byoperating the pump assembly 21, which will draw wash liquid from thesump 11 and to pump the liquid to the port. Alignment of the port 354 inthe diverter disk 352 with one of the passages permits the flow ofliquid to the spray element associated with that passage. For example,when the port 354 is aligned with the first passage 358, liquid isemitted from the mid-level and upper spray arm assemblies 23, 24 via thesupply tube 25. When the port 354 is aligned with the second passage360, liquid is emitted from the spray manifold 52 via the supply conduit58. When the port 354 is aligned with the third passage 362, liquid isemitted from the lower spray arm assembly 22. While not illustratedherein, more than one port 354 can be provided in the diverter disk 352,such that more than one passage 358, 360, 362 can be supplied withliquid at a time.

In an alternate configuration of the liquid supply system of thedishwasher 10, liquid can be provided to the spray manifold 52 at thesame time that liquid is provided to the mid-level and upper spray armassemblies 23, 24. In another configuration, the valve 40 disclosedabove for the first embodiment can be used to divert liquid between thesupply tube 25 and the supply conduit 58.

FIGS. 8 and 9 are front and rear perspective views of the spray manifold52 from FIG. 6. As shown, the spray manifold 52 is configured to havetwo branches, a right branch 64 and a left branch 66, as viewed from theperspective of a user standing in front of and facing the opendishwasher 10 of FIG. 6, which selectively receive wash liquid beingpumped through the supply conduit 58. As shown, the two branches 64, 66may be symmetrically opposing and may be positioned opposite sides ofthe bracket 60. The branches 64, 66 are further positioned on oppositesides of the supply conduit 58, but unlike the position of the branches64, 66 with respect to the bracket 60, are not symmetrically positionedwith respect to the supply conduit 58. In the illustrated configuration,the right branch 64 is closer to the supply conduit 58 than the leftbranch 66. Alternatively, the branches 64, 66 may be non-symmetricaland/or may be provided on the same side of the bracket 60 and/or supplyconduit 58.

Each branch 64, 66 is in fluid communication with the liquiddistribution header 56 and is provided with one or more of the multiplesprayers 54 of the spray manifold 52. As shown herein, each branch 64,66 is provided with two sprayers 54. It is also within the scope of theinvention for each branch 64, 66 to be provided with a different ornon-equal number of sprayers 54.

As illustrated, each sprayer 54 has a generally flat finger-like body 68that extends upwardly from the liquid distribution header 56 to a freeupper end. Each body 68 has an inner surface 70 that faces the washchamber 19 and an outer surface 72 that faces the rear wall 18 of thetub 12 and which is joined to the inner surface 70 by a narrowperipheral side surface 74 that extends around three sides of the body68. The outer surface 72 of one or more of the bodies 68 can include atleast one of the spacers 76; as shown, multiple spacers are provided onthe outer surface 72 of each body 68, and can be arranged as an array ofraised protrusions on the outer surface 72.

Each body 68 has a plurality of apertures 78 configured to spray washliquid outwardly. The inner surface 70 of the body 68 includes raisedprotrusions 80 in which the apertures 78 are formed. Each aperture 78may be substantially oval in shape, although other shapes, such ascircular, are possible. As one of skill in the art will appreciate, thewash liquid being pumped through the supply conduit 58 can be underpressure as it passes through the apertures 78, thereby creating anintensified wash zone. The spray from the apertures 78 collectivelydefine the spray zone 62 directed toward the lower dish rack 26 shown inFIG. 7.

The liquid distribution header 56 has a generally L-shaped body 82having a lower portion 84 that extends outwardly from the supply conduit58 and an upper portion 86 which extends to the sprayers 54. The lowerportion 84 extends generally horizontally and is configured to extendalong the bottom wall 14 of the tub 12 (FIG. 6). The upper portion 86extends generally vertically and is configured to extend along the rearwall 18 of the tub 12 (FIG. 6). The lower and upper portions 84, 86 arejoined together by a curved portion 88 which extends over the cornerbetween the bottom and rear walls 14, 18 (FIG. 6). As shown in FIG. 8,the upper surface of the header body 82 can be relatively smooth andwithout surface features while as shown in FIG. 9, the lower surface ofthe header body 82 can have surface features which designate the flowpaths of liquid through the liquid distribution header 56.

FIG. 10 is a front perspective view of the spray manifold 52, with aportion of the spray manifold 52 cut away to illustrate the liquid flowpaths through the spray manifold 52. Specifically, many of the upper andinner surfaces of the spray manifold 52 are removed for clarity.

The supply conduit 58 comprises an elongated tube 90 defining aninterior supply flow path 92 having a first end defining an inlet 94 ofthe interior supply flow path 92 in fluid communication with a liquidsource, such as the sump 11, and a second end which joins the liquiddistribution header 56 and defines an outlet 96 of the interior supplyflow path 92.

The liquid distribution header 56 defines an interior flow path havingmultiple channels 98, 100 that deliver wash liquid from the supplyconduit 58 to the branches 64, 66. The number of channels can correspondto the number of branches, with each of the channels in fluidcommunication with one corresponding branch. Since the illustratedembodiment has a right and left branch 64, 66, the liquid distributionheader 56 has a corresponding right channel 98 and left channel 100. Thechannels 98, 100 can have a common inlet, namely, the outlet 96 of thesupply conduit 58. However, each channel 98, 100 has its own outlet 102,104, respectively, thereby, fluidly isolating the two branches 64, 66from each other. The outlet can be formed by multiple separate openings,which can correspond to the number of sprayers 54 for each branch 64,66. Since the illustrated embodiment has two sprayers 54 per branch 64,66, the outlet of each channel 98, 100 will have two openings 102, 104.The openings 102, 104 on each branch 64, 66 can be separated from eachother by a divider 107 connecting the peripheral side walls of theadjacent sprayers 54.

Likewise, each branch 64, 66 defines an interior flow path havingmultiple passageways 106 that deliver wash liquid from the liquiddistribution header 56 to the apertures 78 of the sprayers 54. Thenumber of passageways 106 can correspond to the number of sprayers 54,with each of the passageways 106 in fluid communication with onecorresponding sprayer 54. Since the illustrated embodiment has twosprayers 54 for each branch 64, 66, each branch 64, 66 has twocorresponding passageways 106. The passageways 106 can have a commoninlet, namely, the outlet openings 102 or 104 of the channels 98, 100.However, each passageway 106 has its own outlet, collectively defined bythe apertures 78 of the associated sprayer 54, thereby, fluidlyisolating the two sprayers 54 of each branch 64, 66 from each other. Inthe illustrated embodiment, all of the passageways 106 are similar toeach other, and can, therefore, have the same cross-sectional area aseach other.

The tube 90, channels 98, 100, and passageways 106 can collectivelydefine multiple liquid flow paths through the spray manifold 52. Aliquid flow path through the spray manifold 52 can be thought of as theflow path of liquid traveling from the supply conduit 58 to one of thesprayers 54 and through the apertures 78 of that sprayer 54. Thus, thespray manifold 52 shown herein comprises four distinct liquid flowpaths. Under a narrower classification, a liquid flow path through thespray manifold 52 can be thought of as the flow path of liquid travelingfrom the supply conduit 58 to one of the apertures 78 of the sprayermanifold 52. Using this classification, the spray manifold 52 shownherein comprises forty distinct liquid flow paths since forty apertures78 are provided on the spray manifold 52.

The interior flow path of the liquid distribution header 56 can beconfigured to minimize pressure loss from the inlet to the channels 98,100, to the branches 66, 64. The embodiment of the invention shownherein employs multiple techniques for minimizing pressure loss. First,the interior flow path of the liquid distribution header 56 can beconfigured to lack any sharp transitions between the channel 98, 100 andits associated branch 64, 66 to reduce or eliminate any areas ofturbulent flow in the interior flow path. The reduction or eliminationof turbulent flow within the spray manifold 52 can help minimizepressure loss.

As shown in FIG. 10, the channels 98, 100 are formed by a combination ofstraight, curved and angled walls which guide the flow of liquid throughthe channel 98, 100 to the associated branch 64, 66. Specifically, theright channel 98 includes an outer wall 108 and an inner wall 110, bothof which can include smooth transitions along their respective lengths.The outer wall 108 can eventually merge with the peripheral side surface74 of the outermost sprayer 54 on the right branch 64, while the innerwall 110 can likewise eventually merge with the peripheral side surface74 of the innermost sprayer 54 on the right branch 64. The outer wall108 can include a rounded corner 112 that directs liquid toward theoutermost sprayer 54. Furthermore, the divider 107 that separates theoutlet openings 102 of the right channel 98 can be rounded as well.

The left channel 100 includes an outer wall 114 and an inner wall 116,both of which can include smooth transitions along their respectivelengths. The outer wall 114 can eventually merge with the peripheralside surface 74 of the outermost sprayer 54 on the left branch 66, whilethe inner wall 116 can likewise eventually merge with the peripheralside surface 74 of the innermost sprayer 54 on the left branch 66. Theouter wall 114 can also include a rounded corner 118 that directs liquidtoward the outermost sprayer 54. Furthermore, the divider 107 thatseparates the outlet openings 104 of the left channel 100 can be roundedas well.

The rounded corners 112, 118 of each channel 98, 100 can be formed bydepressing sections of the curved portion 88 of the liquid distributionheader 56, which eliminates the otherwise sharp transitions created bythe outer corners of the liquid distribution header 56. As shown, bothcorners of the curved portion 88 are depressed to seal them againstliquid flow, thereby, forming a right upper sealed corner 120 adjacentthe right channel 98 and a left upper sealed corner 122 adjacent theleft channel 100. Thus, while the outer profile of the spray manifold 52may include sharp transitions and corners, the interior flow paththrough the spray manifold 52 can be configured to eliminate these sharptransitions and corners.

The liquid distribution header 56 can include additional depressedsections which define the shape of the channels 98, 100. As shown inFIG. 10, the corners of the lower portion 84 of the liquid distributionheader 56 are depressed to seal them against liquid flow, thereby,forming a right lower sealed corner 124 which defines a portion of theouter wall 108 of the right channel 98 and a left lower sealed corner126 which defines a portion of the outer wall 114 of the left channel100. At least a portion of the inner walls 110, 116 of the channels 98,100 can be defined by depressing a central portion of the header body 82to seal this area against liquid flow, thereby, forming a central sealedarea 128 in the liquid distribution header 56.

A second technique employed by the embodiment of the spray manifold 52shown in the figures for minimizing pressure loss is to configure theinterior flow path of the liquid distribution header 56 such that thevolumetric flow rate requirement of each channel 98, 100 corresponds toor matches that of its associated sprayers 54. Each sprayer 54 has apredetermined minimum volumetric flow rate requirement for producing aneffective spray action from the spray manifold 52. Liquid supplied toany of the sprayers 54 through channel 98 or 100 at the minimum orhigher volumetric flow rate required for the sprayer 54 can produce aneffective spray action. Effective spray action is essentially acontinuous or near-continuous spray of liquid from the sprayer 54 that,at a minimum, reaches utensil items within the spray zone 62, but, atits maximum, will not move the utensil items. The liquid pressure at thesprayer 54 can also be sufficient to reach the tallest utensil item thatwill fit in the spray zone 62 of the lower dish rack 26.

In embodiments where the sprayers 54 are organized on differentbranches, such as in the illustrated embodiment where two sprayers 54are provided per branch 64, 66, the volumetric flow rate requirement ofeach branch 64, 66 can correspond directly to the volumetric flow raterequirements of the sprayers 54 provided on each branch 64, 66; morespecifically, the volumetric flow rate requirement of each branch 64, 66will be approximately the sum of the volumetric flow rate requirementsof the sprayers 54 provided thereon. In this case, the interior flowpath of the liquid distribution header 56 can be configured such thatthe volumetric flow rate requirement of each channel 98, 100 correspondsto or matches that of its associated branch 64, 66.

The volumetric flow rate through each portion of the spray manifold 52,whether it is one of the sprayers 54, one of the branches 64, 66, or oneof the channels 98, 100, may be quantified as a function of the volumeof liquid which passes through a given cross-sectional area of theportion and the velocity of the liquid flowing through the portion. Inthis case, since liquid is supplied to the spray manifold 52 from acommon source, i.e. from the supply conduit 58, the velocity of theliquid flowing through each portion of the spray manifold 52 will beabout equal. Furthermore, in this case, the individual sprayers 54 areidentical to each other, and, therefore, have the same cross-sectionalarea at given planes through the sprayers 54 and may accommodate thesame volume of liquid. The channels 98, 100 may also have the samecross-sectional area since each feeds an equal number of identicalsprayers 54. However, the cross-sectional area of the liquid flow pathsthrough the channels 98, 100 in the location of the liquid distributionheader 56 may be different for each channels 98, 100. Thecross-sectional area of the liquid flow paths through the channels 98,100 may be proportional to the total requirement on each branch 64, 66.For example, if the right branch 64 were instead provided with threesprayers 54 while the left branch 66 were provided with one sprayer 54,then the cross-sectional area of the right channel 98 would be threetimes greater than that of the left channel 100. Furthermore, the inletand outlet of the interior flow path of the liquid distribution header56 can have equal cross-sectional areas.

Due to the off-center placement of the supply conduit 58 with respect tothe liquid distribution header 56, proper distribution of liquid to thesprayers 54 in order to meet their respective volumetric flow raterequirements can be problematic. The liquid distribution header 56 cancomprise a flow diverter 130 for proportionally dividing the liquidsupplied from the supply conduit 58 to the multiple sprayers 54 inproportion to the volumetric flow rate requirement of each sprayer. Theflow diverter 130 can be a stationary formation in the liquiddistribution header 56 that is positioned in opposing relationship tothe outlet opening 96 of the supply conduit 58. The flow diverter 130can be located to proportionally divide the cross-sectional area of theoutlet opening 96 in correspondence with the volumetric flow raterequirement of the sprayers 54. In the illustrated embodiment, since theoutlet opening 96 is positioned closer to the right branch 64 than theleft branch 66, a greater amount of incoming liquid tends to flow towardthe right branch 64. However, the flow diverter 130 directs a portion ofthat liquid back toward the left branch 66 such that the volumetric flowrequirements of each branch 64, 66, and thus each sprayer 54, are met.

In embodiments where the sprayers 54 are organized on differentbranches, such as in the illustrated embodiment where two sprayers areprovided per branch 64, 66, the flow diverter 130 can proportionallydivide the liquid supplied from the supply conduit 58 in proportion tothe volumetric flow rate requirement of each branch 64, 66, which isnecessarily dependent on the volumetric flow rate requirement of thesprayers 54 provided on each branch 64, 66. The flow diverter 130 can belocated to proportionally divide the cross-sectional area of the outletopening 96 in correspondence with the volumetric flow rate requirementof the two branches 64, 66, i.e. the sum of the volumetric flow raterequirements of the sprayers 54 provided on each branch 64, 66.

FIG. 11 is a top view of a portion of FIG. 10, illustrating the flowdivider 130. The flow diverter 130 can comprise a deflector wall 132positioned in opposing relationship to the outlet opening 96 of thesupply conduit 58 and a nose 134 from which the deflector wall 132extends and that is configured to divide the liquid supplied from thesupply conduit 58 into two separate flows. As shown herein, thedeflector wall 132 is positioned to guide wash liquid to the left branch66, and can be shaped in accordance with the volumetric needs of theleft branch 66. The illustrated deflector wall 132 includes an angledportion 136 extending away from the nose 134 at an incline to the outletopening 96, a relatively straight portion 138, and a curved transitionportion 140 which joins the angled portion 136 with the straight portion138. The straight portion 138 merges with the inner wall 116 of the leftchannel 100. The nose 134 merges with the inner wall 110 of the rightchannel 98.

In operation, as liquid is supplied to the spray manifold 52, due to theoff-center placement of the supply conduit 58, a greater amount ofincoming liquid tends to flow toward the right branch 64 than the leftbranch 66. However, the configuration of the liquid distribution header56 acts to proportionally distribute the liquid to each branch 64, 66according to the volumetric flow rate requirement of each sprayer 54 onthe branch 64, 66. In the illustrated embodiment, the flow diverter 130directs a portion of the liquid back toward the left branch 66 such thatthe volumetric flow requirements of each branch 64, 66, and, thus, eachsprayers 54, are met. The flow diverter 130 divides the liquid into twoflows of liquid, one directed toward the right branch 64 and onedirected toward the left branch 66. However, in other embodiments wheremore than two branches are provided, the liquid distribution header 56can be configured such that liquid is divided into more than two flows,which may be accomplished, for example, by providing multiple flowdiverters 130.

The liquid flow directed toward each branch 64, 66 will be furtherdivided into two flows by the divider 107, each going into a differentlateral passageway 106. In each passageway 106, the liquid will besprayed from the apertures 78 in the sprayer 54.

The passageways 106 are configured to supply liquid to the sprayers 54at the same volumetric flow rate. In the illustrated embodiment, sinceeach sprayer 54 has the same configuration, liquid will be emitted fromeach sprayer 54 at the same flow rate, which creates a consistentcleaning effect across the spray zone 62 of the spray manifold 52.

Also during operation, liquid may be sprayed from one or more of thespray arm assemblies 22, 23, 24 provided in the treating chamber 19 ofFIG. 7. In this manner, multiple spray zones may be created within thetreating chamber 19, each associated with one of the spray armassemblies 22, 23, 24 or with the spray manifold 52, to provide anenhanced cleaning operation.

FIGS. 12 and 13 are schematic front and side views of the spray manifold52, illustrating the spray pattern of wash liquid from the spraymanifold 52. The apertures 78 can be configured to optimize the coverageprovided by the spray manifold 52. For example, the apertures 78 can bearranged in a pattern that varies the vertical and horizontal locationof the apertures 78 on each sprayer 54. The pattern can be asymmetricalwith respect to each sprayer 54, or across the spray manifold 52.Furthermore, the apertures 78 can be oriented on the sprayers 54 to emita spray of wash liquid in different directions, when viewed from thefront as shown in FIG. 12 or when viewed from the side as shown in FIG.13. As shown in FIGS. 12 and 13, the apertures can be oriented to sprayliquid substantially horizontally as indicated by A, laterally outwardlytoward one side of the dish rack 26 as indicated by B, laterallyoutwardly toward an opposite side of the dish rack 26 as indicated by Cor at an upwardly angle as indicated by D. While not shown, theapertures 78 can also be oriented to spray liquid at a downward angle.The coverage pattern of the apertures 78 shown herein is configured tobe a suitable for larger utensil items, specifically a 9″×13″ dish orpan P. Other coverage patterns suitable for other utensil items are alsopossible. It is noted that the lines A, B, C, and D in FIGS. 12 and 13represent the center line for the spray emanating from the correspondingaperture 78. In reality, the emanating spray will fan out, typically ina cone-shaped pattern, about the corresponding centerline.

FIG. 14 is a perspective view of a dishwasher 10 having a spray manifold150 in accordance with a third embodiment of the present invention. Thedishwasher 10 can be substantially similar to the dishwasher 10 shown inFIG. 1, with the exception the spray manifold 150 is employed in placeof the spray manifold 29.

The spray manifold 150 comprises multiple sprayers 152, 154 throughwhich liquid is sprayed into the wash chamber 19. The sprayers includeone or more rotating sprayers 152 and one or more stationary sprayers154. The sprayers 152, 154 are fluidly coupled to a common liquiddistribution header 156. A supply conduit 158 supplies liquid to thespray manifold 150 from a liquid source and is fluidly coupled to theliquid distribution header 156. A bracket 160 positioned between thesprayers 152, 154 is used to couple the spray manifold 150 to the tub12, and can extend around the supply tube 25 to secure to the spraymanifold 150 to the rear wall 18 of the tub 12.

FIG. 15 is a schematic, cross-sectional view of the dishwasher 10 shownin FIG. 13. The spray manifold 150 can be positioned adjacent the rearwall 18 of the interior tub 12 adjacent the lower dish rack 26. In thisway, a flow of wash liquid is directed toward the lower dish rack 26from the manifold thereby providing a second utensil or wash zone 162.Like the first embodiment, the first wash zone 50 is provided by thespray of wash liquid from any one or combination of the spray armassemblies 22, 23, 24. The spray manifold 150 can extend in generallyhorizontal manner across a partial width of the lower dish rack 26.However, the spray manifold 150 may extend across virtually any width ofthe rack 26 or tub 12. Furthermore, one or more of the multiple sprayers152, 154 can extend above an upper edge 164 of the lower dish rack 26such that the sprayers 152, 154 not only spray through the side of thelower dish rack 26, but also across the top of the lower dish rack 26.As shown herein, the rotating sprayers 152 are positioned to spraythrough the side of the lower dish rack 26, while the stationarysprayers 154 are positioned to spray across the top of the lower dishrack 26. The position of the spray manifold 150 shown, particularly thesprayers 152, 154 provided both below and above the upper edge 164 ofthe lower dish rack 26, allows for casserole dishes or 9″×13″ pans to beloaded into the lower dish rack 26 in an upright position, which helpsmaximize or optimize amount of dishware that can be loaded in any givencycle while still effectively cleaning the casserole dish or 9″×13″ pan.

The spray manifold 150 can include at least one spacer 166 that providesa gap between the rear side of the spray manifold 150 and the rear wall18 of the tub 12. As shown, multiple spacers 166 are provided on thespray manifold 150. The gap created by the spacers 166 permits some washliquid to flow between the spray manifold 150 and the tub 12, whichrinses soil out of the gap and prevents the accumulation of soil behindthe spray manifold 150.

Like the second embodiment, the third embodiment of the spray manifold150 is configured to receive wash liquid from a separate and dedicatedsupply conduit 158. Therefore, rather than being in fluid communicationwith the supply tube 25 that provides liquid to either or both of themid-level and upper spray arm assemblies 23, 24, as in the firstembodiment, the spray manifold 150 receives liquid via its own supplyconduit 158 that extends along the bottom wall of the tub 12 to theliquid distribution header 156. While not shown herein, the dishwasher10 of the third embodiment can employ the liquid supply system shown inFIG. 7A and the valve mechanism 350 shown in FIG. 7A can be providedsuch that only one of the supply tube 25 and supply conduit 158 canreceive liquid at one time. In an alternate configuration, liquid can besupplied to the supply tube 25 and supply conduit 158 at the same time.In another configuration, the valve 40 disclosed above for the firstembodiment can be used to divert wash liquid between the supply tube 25and the supply conduit 158.

FIGS. 16 and 17 are front and rear perspective views of the spraymanifold 150 from FIG. 14. As shown, the spray manifold 150 isconfigured to have two branches, a right branch 168 and a left branch170as viewed from the perspective of a user standing in front of andfacing the open dishwasher 10 of FIG. 14, which selectively receiveliquid being pumped through the supply conduit 158. As shown, the twobranches 168, 170 may be symmetrically opposing and may be positionedopposite sides of the bracket 160. The branches 168, 170 are furtherpositioned on opposite sides of the supply conduit 158, but unlike theposition of the branches 168, 170 with respect to the bracket 160, arenot symmetrically positioned with respect to the supply conduit 158. Inthe illustrated configuration, the right branch 168 is closer to thesupply conduit 158 than the left branch 170. Alternatively, the branches168, 170 may be non-symmetrical and/or may be provided on the same sideof the bracket 160 and/or supply conduit 158.

Each branch 168, 170 is in fluid communication with the liquiddistribution header 156 and is provided with one or more of the multiplesprayers 152, 154 of the spray manifold 150. As shown herein, eachbranch 168, 170 is provided with two rotating sprayers 152 and onestationary sprayer 154. It is also within the scope of the invention foreach branch 168, 170 to be provided with a different or non-equal numberof sprayers 152, 154.

As illustrated, each branch has a shorter lateral body 172 and a longermedial body 174 extending upwardly from the liquid distribution header156 to a free upper end. The lateral body 172 is generally flat and hasan inner surface 176 that faces the wash chamber 19 and an outer surface178 that faces the rear wall 18 of the tub 12 and which is joined to theinner surface 176 by a narrow peripheral side surface 180 that extendsaround three sides of the body 172. The medial body 174 is generallyflat and has an inner surface 182 that faces the wash chamber 19 and anouter surface 184 that faces the rear wall 18 of the tub 12 and which isjoined to the inner surface 182 by a narrow peripheral side surface 186that extends around three sides of the body 174. The lateral body 172comprises one rotating sprayer 152 provided in its inner surface 176,while the medial body 174 comprises one rotating sprayer 152 and onestationary sprayer 154 provided on its inner surface 182. The outersurfaces 178, 184 of the lateral and medial bodies 172, 174 can includeat least one of the spacers 166; as shown, multiple spacers 166 areprovided on the outer surface 178, 184 of each body 172, 174, and can bearranged as an array of raised protrusions on the outer surface 178,184.

The liquid distribution header 156 has a generally L-shaped body 188having a lower portion 190 that extends outwardly from the supplyconduit 158 and an upper portion 192 which extends to the sprayers 152,154. The lower portion 190 extends generally horizontally and isconfigured to extend along the bottom wall 14 of the tub 12 (FIG. 6).The upper portion 192 extends generally vertically and is configured toextend along the rear wall 18 of the tub 12 (FIG. 6). The lower andupper portions 190, 192 are joined together by a curved portion 194which extends over the corner between the bottom and rear walls 14, 18(FIG. 6). As shown in FIG. 16, the upper surface of the header body 188can be relatively smooth and without surface features while as shown inFIG. 17, the lower surface of the header body 188 can have surfacefeatures which designate the flow paths of liquid through the liquiddistribution header 156.

FIG. 18 is an exploded view of the right branch 168 of the spraymanifold 150, illustrating the components of the rotating sprayers 152.Each rotating sprayer 152 includes a spray head having a rear sprayerbody 196, a hub 198 which couples the rear sprayer body 196 to thesprayer bodies 172, 174, a retainer 200 which retains the hub 198 on thebranch bodies 172, 174, and a front sprayer body comprising a cap 202mounted to the front of the rear sprayer body 196.

The rear body 196 comprises a rear surface 204 and a peripheral sidesurface 206 that is generally circular in shape, with the exception oftwo notched sections 208. The rear surface 204 includes a centralopening 210 and a guide wall 212 spaced inwardly of the peripheral sidesurface 206 that extends along the majority of the peripheral sidesurface 206, with the exception of breaks or openings 214 provided inalignment with the notched sections 208. The peripheral side surface 206is provided with one or more coupling features, shown herein as spacedresilient tabs 216.

The hub 198 includes a body having a radially extending flange 218 onone end and which is joined to a female connector 220 by a frame 222extending from the flange 218 to the female connector 220. The frame 222includes one or more openings 224 which permit the passage of liquidinto the rotating sprayer 152.

The retainer 200 includes a head 226 attached to a male connector 228which is received by the female connector 220 on the hub 198. The maleand female connectors 228, 220 can be configured for a friction orinterference fit fastening.

The cap 202 comprises a front surface 230 and a peripheral side surface232 that is generally circular in shape, with the exception of twonotched sections 234.

The cap 202 includes a plurality of primary apertures 236 configured tospray wash liquid outwardly from the cap 202. The front surface 230 ofthe cap 202 can include raised protrusions 238 having an angled face 240in which the apertures 236 are formed. Each aperture 236 may besubstantially circular in shape, although other shapes, such as oval,are possible. The angled faces 240, and, thus, the apertures 236, can beoriented in different directions; as shown herein, the faces 240 arearranged in opposing pairs, such that the spray of liquid from theapertures 236 covers a wider area.

FIG. 19 is a rear view of the cap 202. The cap 202 can further include aplurality of secondary apertures 242 configured to spray liquidperipherally from the cap 202. The secondary apertures 242 are formed inthe notched sections 234 of the peripheral side surface 232. Twosecondary apertures 242 can be provided, and can be diametricallyopposing such that the apertures 242 spray in opposite directions andproduce a driving force to rotate the sprayer 152.

The cap 202 further includes a guide wall 246 spaced inwardly of theperipheral side surface 232 that extends along the majority of theperipheral side surface 232, with the exception of breaks or openings248 provided in alignment with the notched sections 234. The guide wall246 of the cap 202 can be aligned with the guide wall 212 on the rearbody 196 (FIG. 18). The inner surface of the cap 202 can comprise aplurality of spaced guide vanes 250 that radiate from a central portion252. As shown herein, the guide vanes 250 can extend between adjacentapertures 236 and can be oriented to deflect liquid toward the apertures236.

Referring back to FIG. 18, the peripheral side surface 232 is furtherprovided with one or more complementary coupling features, shown hereinas spaced detents 244 that are received by the tabs 216 for attachingthe cap 202 to the rear body 196, thereby defining a fluid chamberbetween the cap 202 and rear body 196, the fluid chamber having an inletprovided by the central opening 210 of the rear body 196 and an outletprovided by the primary and secondary apertures 236, 242 in the cap 202.When attached, the peripheral side surfaces 206, 232 and notchedsections 208, 234 of the rear body 196 and cap 202 are mated.

The inner surfaces 176, 182 of the lateral and medial bodies 172, 174each include a raised platform 254 on which the rotating sprayers 152are mounted. The platform 254 can include a central opening 256 in fluidcommunication with the central opening 210 of the rear body 196, and atleast one spacer 258 that provides a gap between the rear side of therotating sprayer 152 and the platform 254. As shown, multiple spacers258 are provided on the platform 254. The gap created by the spacers 258permits some wash liquid to flow between the rotating sprayer 152 andthe platform 254, which rinses soil out of the gap and prevents theaccumulation of soil behind the rotating sprayer 152.

The stationary sprayer 154 is provided above the rotating sprayer 152,and includes a plurality of apertures 260 configured to spray washliquid outwardly. The inner surface 182 of the medial body 174 includesa raised circular protrusion 262 in which the apertures 260 are formed.The apertures 260 can be a mixture of oval and circular openings,although other shapes are possible. As one of skill in the art willappreciate, the liquid being pumped through the supply conduit 158 canbe under pressure as it passes through the various apertures 236, 242,260 of the rotating and stationary sprayers 152, 154, thereby, creatingan intensified wash zone. The spray from the apertures collectivelydefine the spray zone 162 directed toward the lower dish rack 26 shownin FIG. 15.

The stationary sprayers 154, liquid distribution header 156, supplyconduit 158, and bracket 160 can be integrally formed together as asingle molded piece. The rotating sprayers 152 can be separately formedand mounted to the spray manifold 150. Alternatively, one or more of theother components of the spray manifold 150 can be formed separately andphysically coupled together, using suitable sealing means as needed tocreate a fluid-tight spray manifold 150.

FIG. 20 is a front perspective view of the spray manifold 150, with aportion of the spray manifold 150 cut away to illustrate the liquid flowpaths through the spray manifold 150. Specifically, many of the upperand inner surfaces of the spray manifold 150 are removed for clarity.The supply conduit 158 comprises an elongated tube 264 defining aninterior supply flow path 266 having a first end defining an inlet 268of the interior supply flow path 266 in fluid communication with aliquid source, such as the sump 11, and a second end which joins theliquid distribution header 156 and defines an outlet 270 of the interiorsupply flow path 266.

The liquid distribution header 156 defines an interior flow path havingmultiple channels 272, 274 that deliver wash liquid from the supplyconduit 158 to the branches 168, 170. The number of channels cancorrespond to the number of branches, with each of the channels in fluidcommunication with one corresponding branch. Since the illustratedembodiment has a right and left branch 168, 170, the liquid distributionheader 156 has a corresponding right channel 272 and left channel 274.The channels 272, 274 can have a common inlet, namely, the outlet 270 ofthe supply conduit 158. However, each channel 272, 274 has its ownoutlet 276, 278, respectively, thereby, fluidly isolating the twobranches 168, 170 from each other. The outlet can be formed by multipleseparate openings, which can correspond to the number of sprayer bodies172, 174 for each branch 168, 170. Since the illustrated embodiment hastwo sprayer bodies 172, 174 per branch 168, 170, the outlet of eachchannel 272, 274 will have two openings 276, 278. The openings 276, 278on each branch 168, 170 can be separated from each other by a divider280 connecting the peripheral side surfaces 180, 186 of the adjacentsprayer bodies 172, 174.

Likewise, each branch 168, 170 defines an interior flow path havingmultiple passageways 282, 284 that deliver wash liquid from the liquiddistribution header 156 to the various apertures 236, 242, 260 of therotating and stationary sprayers 152, 154. The number of passageways282, 284 can correspond to the number of sprayer bodies 172, 174, witheach of the lateral passageways 282 in fluid communication with thelateral sprayer bodies 172 and the medial passageways 284 in fluidcommunication with the medial sprayer bodies 174. Since the illustratedembodiment has one lateral and one medial sprayer body 172, 174 for eachbranch 168, 170, each branch 168, 170 has one corresponding lateral andone corresponding medial passageway 282, 284. The passageways 282, 284can have a common inlet, namely, the outlet openings 276 or 278 of thechannels 272, 274. However, each passageway 282, 284 has its own outlet,with the lateral passageway 282 having the apertures 236, 242 of therotating sprayer 152 as outlets, and the medial passageway 284 havingthe apertures 236, 242 of the rotating sprayer 152 as well as theapertures 260 of the stationary sprayer as outlets (see FIG. 16). Thus,the sprayers 152, 154 on different sprayer bodies 172, 174 are fluidlyisolated from each other. In the illustrated embodiment, the two lateralpassageways 282 are similar to each other, and can, therefore, have thesame cross-sectional area as each other. Likewise, the medialpassageways 284 are similar to each other, and can therefore have thesame cross-sectional areas as each other.

FIG. 21 is a rear perspective view of the right branch 168 of the spraymanifold 150, with a portion of the spray manifold 150 cut away toillustrate the liquid flow paths through the spray manifold 150.Specifically, many of the rear surfaces of the spray manifold 150 areremoved for clarity. In the illustrated embodiment, the liquid flowpaths through each branch 168, 170 will be similar. Each lateralpassageway 282 can have a sickle shaped path, with an angled proximalportion 286 and a curved distal portion 288 that terminates in an outletdefined by the central opening 256 in the lateral body 172. Thus,incoming liquid to the rotating sprayer 152 is directed in a swirlingpattern toward the central opening 256.

Each medial passageway 284 has a dual path for supplying liquid to boththe rotating sprayer 152 and the stationary sprayer 154. The first path,which supplies the rotating sprayer 152, can be sickle shaped, with anangled proximal portion 290 and a curved distal portion 292 thatterminates in an outlet defined by the central opening 256 in the medialbody 174. The second path, which supplies the stationary sprayer 154,can extend as an offshoot from the first path, and can include avertical passageway 294 which opens into a cavity 296 in which theapertures 260 are provided. The cavity 296 can be semi-hemispherical inshape, formed by a flat bottom wall 298 provided at approximately themiddle of the circular protrusion 262 in which the apertures 260 areprovided

The tube 264, channels 272, 274, and passageways 282, 284 cancollectively define multiple liquid flow paths through the spraymanifold 150. A liquid flow path through the spray manifold 150 can bethought of as the flow path of liquid traveling from the supply conduit158 to one of the sprayers 152, 154. Thus, the spray manifold 150 shownherein comprises six distinct liquid flow paths. Under a narrowerclassification, a liquid flow path through the spray manifold 150 can bethought of as the flow path of liquid traveling from the supply conduit158 to one of the apertures 236, 242, 260 of the sprayer manifold 150.Using this classification, the spray manifold 150 shown herein comprisesthirty distinct liquid flow paths since thirty apertures 236, 242, 260are provided on the spray manifold 150.

The interior flow path of the liquid distribution header 156 can beconfigured to minimize pressure loss from the inlet to the channels 272,274, to the branches 168, 170. The embodiment of the invention shownherein employs multiple techniques for minimizing pressure loss. First,the interior flow path of the liquid distribution header 156 can beconfigured to lack any sharp transitions between the channel 272, 274and its associated branch 168, 170 to reduce or eliminate any areas ofturbulent flow in the interior flow path. The reduction or eliminationof turbulent flow within the liquid distribution header 156 can helpminimize pressure loss in the spray manifold 150.

As shown in FIG. 20, the channels 272, 274 are formed by a combinationof straight, curved and angled walls which guide the flow of liquidthrough the channel 272, 274 to the associated branch 168, 170.Specifically, the right channel 272 includes an outer wall 300 and aninner wall 302, both of which can include smooth transitions along theirrespective lengths. The outer wall 300 can eventually merge with theperipheral side surface 180 of the lateral sprayer body 172 on the rightbranch 168, while the inner wall 302 can extend upwardly into the medialsprayer body 174 to define a portion of the medial passageway 284. Theouter wall 300 can include a rounded corner 304 that directs liquidtoward the lateral sprayer body 172. Furthermore, the divider 280 thatseparates the outlet openings 276 of the right channel 272 can berounded as well.

The left channel 274 includes an outer wall 306 and an inner wall 308,both of which can include smooth transitions along their respectivelengths. The outer wall 306 can eventually merge with the peripheralside surface 180 of the lateral sprayer body 172 on the left branch 170,while the inner wall 308 can likewise eventually merge with theperipheral side surface 186 of the medial sprayer body 174 on the leftbranch 170. The outer wall 306 can also include a rounded corner 310that directs liquid toward the lateral sprayer body 172. Furthermore,the divider 280 that separates the outlet openings 278 of the leftchannel 274 can be rounded as well.

The rounded corners 304, 310 of each channel 272, 274 can be formed bydepressing sections of the curved portion 194 of the liquid distributionheader 156, which eliminates the otherwise sharp transitions created bythe outer corners of the liquid distribution header 156. As shown, bothcorners of the curved portion 194 are depressed to seal them againstliquid flow, thereby, forming a right upper sealed corner 312 adjacentthe right channel 272 and a left upper sealed corner 314 adjacent theleft channel 274. Thus, while the outer profile of the spray manifold150 may include sharp transitions and corners, the interior flow paththrough the spray manifold 150 can be configured to eliminate thesesharp transitions and corners.

The liquid distribution header 156 can include additional depressedsections which define the shape of the channels 272, 274. As shown inFIG. 20, the corners of the lower portion 190 of the liquid distributionheader 156 are depressed to seal them against liquid flow, therebyforming a right lower sealed corner 316 which defines a portion of theouter wall 300 of the right channel 272 and a left lower sealed corner318 which defines a portion of the outer wall 306 of the left channel274. At least a portion of the inner walls 302, 308 of the channels 272,274 can be defined by depressing a central portion of the header body188 to seal this area against liquid flow, thereby forming a centralsealed area 320 in the liquid distribution header 156.

The passageways 282, 284 can also be configured to lack any sharptransitions to reduce or eliminate any areas of turbulent flow in theinterior flow paths of the sprayer bodies 172, 174. The reduction orelimination of turbulent flow within the sprayer bodies 172, 174 canalso help minimize pressure loss in the spray manifold 150. The branches168, 170 can include additional depressed sections which define theshape of the passageways 282, 284. The passageways 282, 284 can beformed by a combination of straight, curved and angled walls which guidethe flow of liquid through the passageways 282, 284 to the associatedsprayers 152, 154. As shown in FIGS. 20 and 21, the lateral sprayerbodies 172 have irregularly-shaped depressions that are sealed againstliquid flow, thereby, forming lateral sealed areas 322 that define thesickle shape of the lateral passageways 282. The medial sprayer bodies174 have irregularly-shaped depressions that are sealed against liquidflow, thereby forming lower and upper medial sealed areas 324, 326 thatdefine the dual paths of the medial passageways 284.

A second technique employed by the embodiment of the spray manifold 150shown in the figures for minimizing pressure loss is to configure theinterior flow path of the liquid distribution header 156 such that thevolumetric flow rate requirement of each channel 272, 274 corresponds toor matches that of its associated sprayers 152, 154. Each sprayer 152,154 has a predetermined minimum volumetric flow rate requirement forproducing a continuous or near-continuous spray of liquid. If liquid issupplied to one of the sprayers 152, 154 below its required volumetricflow rate, the spray of liquid produced by the sprayer can sputterintermittently, which reduces the cleaning effect of the spray manifold150.

In embodiments where the sprayers 152, 154 are organized on differentbranches, such as in the illustrated embodiment where two rotatingsprayers 152 and one stationary sprayer 154 are provided per branch 168,170, the volumetric flow rate requirement of each branch 168, 170 cancorrespond directly to the volumetric flow rate requirements of thesprayers 152, 154 provided on each branch 168, 170; more specifically,the volumetric flow rate requirement of each branch 168, 170 will beapproximately the sum of the volumetric flow rate requirements of thesprayers 152, 154 provided thereon. In this case, the interior flow pathof the liquid distribution header 156 can be configured such that thevolumetric flow rate requirement of each channel 272, 274 corresponds toor matches that of its associated branch 168, 170.

The volumetric flow rate through each portion of the spray manifold 150,whether it be one of the sprayers 152, 154, one of the branches 168,170, or one of the channels 272, 274, may be quantified as a function ofthe volume of liquid which passes through a given cross-sectional areaof the portion and the velocity of the liquid flowing through theportion. In this case, since liquid is supplied to the spray manifold150 from a common source, i.e. from the supply conduit 158, the velocityof the liquid flowing through each portion of the spray manifold 150will be about equal. However, the rotating and stationary sprayers 152,154 have different cross-sectional areas and may accommodate unequalvolumes of liquid. Additionally, since the medial sprayer bodies 174supply both a rotating sprayer 152 and a stationary sprayer 154 whilethe lateral sprayer bodies 172 supply only a rotating sprayer, a greatervolume of liquid should be supplied to the medial sprayer bodies 174than the lateral sprayer bodies 174.

The channels 272, 274 may have the same cross-sectional area since eachfeeds an equal number of identical sprayers 152, 154. However, thecross-sectional area of the liquid flow paths through the channels 272,274 in the location of the liquid distribution header 56 may bedifferent for each channels 272, 274. Furthermore, the inlet and outletof the interior flow path of the liquid distribution header 156 can haveequal cross-sectional areas.

Due to the off-center placement of the supply conduit 158 with respectto the liquid distribution header 156, proper distribution of liquid tothe sprayers 152, 154 in order to meet their respective volumetric flowrate requirements can be problematic. The liquid distribution header 156can comprise a flow diverter 328 for proportionally dividing the liquidsupplied from the supply conduit 158 to the multiple sprayers 152, 154in proportion to the volumetric flow rate requirement of each sprayer152, 154. The flow diverter 328 can be a stationary formation in theliquid distribution header 156 that is positioned in opposingrelationship to the outlet opening 270 of the supply conduit 158. Theflow diverter 328 can be located to proportionally divide thecross-sectional area of the outlet opening 270 in correspondence withthe volumetric flow rate requirement of the sprayers 152, 154. In theillustrated embodiment, since the outlet opening 270 is positionedcloser to the right branch 168 than the left branch 170, a greateramount of incoming liquid tends to flow toward the right branch 168.However, the flow diverter 328 directs a portion of that liquid backtoward the left branch 170 such that the volumetric flow requirements ofeach branch 168, 170, and, thus, each sprayer 152, 154, are met.

In embodiments where the sprayers 152, 154 are organized on differentbranches, such as in the illustrated embodiment where two sprayers areprovided per branch 168, 170, the flow diverter 328 can proportionallydivide the liquid supplied from the supply conduit 158 in proportion tothe volumetric flow rate requirement of each branch 168, 170, which isnecessarily dependent on the volumetric flow rate requirement of thesprayers 152, 154 provided on each branch 168, 170. The flow diverter328 can be located to proportionally divide the cross-sectional area ofthe outlet opening 270 in correspondence with the volumetric flow raterequirement of the two branches 168, 170, i.e. the sum of the volumetricflow rate requirements of each sprayer 152, 154 provided on each branch168, 170.

FIG. 22 is a top view of a portion of FIG. 20, illustrating the flowdivider 328. The flow diverter 328 can comprise a deflector wall 330positioned in opposing relationship to the outlet opening 270 of thesupply conduit 158 and a nose 332 from which the deflector wall 330extends and that is configured to divide the liquid supplied from thesupply conduit 158 into two separate flows. As shown herein, thedeflector wall 330 is positioned to guide wash liquid to the left branch170, and can be shaped in accordance with the volumetric needs of theleft branch 170. The illustrated deflector wall 330 includes an angledportion 334 extending away from the nose 332 at an incline to the outletopening 270, a relatively straight portion 336, and a curved transitionportion 338 which joins the angled portion 334 with the straight portion338. The straight portion 336 merges with the inner wall 308 of the leftchannel 274. The nose 332 merges with the inner wall 302 of the rightchannel 272.

In operation, as liquid is supplied to the spray manifold 150, due tothe off-center placement of the supply conduit 158, a greater amount ofincoming liquid tends to flow toward the right branch 168 than the leftbranch 170. However, the configuration of the liquid distribution header156 acts to proportionally distribute the liquid to each branch 168, 170according to the volumetric flow rate requirement of each sprayer 152,154 on the branch 168, 170. In the illustrated embodiment, the flowdiverter 328 directs a portion of the liquid back toward the left branch170 such that the volumetric flow requirements of each branch 168, 170,and, thus, each sprayer 152, 154, are met. The flow diverter 328 dividesthe liquid into two flows of liquid, one directed toward the rightbranch 168 and one directed toward the left branch 170. However, inother embodiments where more than two branches are provided, the liquiddistribution header 156 can be configured such that liquid is dividedinto more than two flows, which may be accomplished, for example, byproviding multiple flow diverters 328.

The liquid flow directed toward each branch 168, 170 will be furtherdivided into two flows by the divider 280, a lateral flow directed intothe lateral passageway 282 and a medial flow directed toward the medialpassageway 284. In the lateral passageway 282, the liquid flow willfollow the interior sickle shaped path to the associated rotatingsprayer 152, and liquid will be sprayed from the apertures 236, 242 inthe rotating sprayer 152. In the medial passageway 282, the liquid flowwill be further divided into two flows, one which will follow the firstinterior sickle shaped path to the associated rotating sprayer 152 suchthat liquid is sprayed from the apertures 236, 242, and one which willfollow the second path to the associated stationary sprayer 154 suchthat liquid is sprayed from the apertures 260.

The passageways 282, 284 are configured to supply liquid to the rotatingsprayers 152 at the same volumetric flow rate. In the illustratedembodiment, since each rotating sprayer 152 has the same configuration,liquid will be emitted from each rotating sprayer 152 at the same flowrate. Likewise, the medial passageways 284 are configured to supplyliquid to the stationary sprayers 154 at the same volumetric flow rate.In the illustrated embodiment, since each stationary sprayer 154 has thesame configuration, liquid will be emitted from each stationary sprayer154 at the same flow rate. This in combination with the spray emittedfrom the rotating sprayers 152 creates a consistent cleaning effectacross the spray zone 162 of the spray manifold 150.

Also during operation, liquid may be sprayed from one or more of thespray arm assemblies 22, 23, 24 provided in the treating chamber 19 ofFIG. 14. In this manner, multiple spray zones may be created within thetreating chamber 19, each associated with one of the spray armassemblies 22, 23, 24 or with the spray manifold 150, to provide anenhanced cleaning operation.

As one of skill in the art should recognize, the spray manifolds 29, 52,150 shown herein are not limited to the location within the dishwasher10 shown in the drawings; rather, the spray manifold 29, 52, 150 couldbe located in virtually any part of the interior tub 12. For example,the spray manifold 29, 52, 150 could be moved up vertically along anyportion of the rear wall 18, such as to a position adjacent the upperdish rack 27. Alternatively, the spray manifold 29, 52, 150 could bepositioned underneath the lower dish rack 26, adjacent or beneath thelower spray arm assembly 22. The spray manifold 29, 52, 150 could alsobe positioned on a different wall of the tub 12, including the top wall13, the bottom wall 14, either side wall 15, 16, or the front wall 17.Alternatively, the spray manifold 29, 52, 150 can be located withineither dish rack 26, 27. Furthermore, the spray manifold 29, 52, 150 canbe adjacent to, on, abutting, or integrated with whichever wall or rackof the dishwasher 10 the spray manifold 29, 52, 150 is associated with.

Positioning the spray manifold 29, 52, 150 at different locations withinthe interior tub 12 of the dishwasher can also affect the direction inwhich the flow of wash liquid is directed from the spray manifold 29,52, 150, thereby affecting the location of the second wash zone 28, 62,162. The spray of liquid from the spray manifold 29, 52, 150 can extendthrough any portion or portions of either dish rack 26, 27. For example,the spray may travel through any side, including the bottom or top side,of either dish rack 26, 27. In the case of the spray manifold 29, 52,150 mounted within either dish rack 26, 27, the spray manifold 29, 52,150 can spray liquid within the interior of the rack 26, 27.

The spray manifolds 29, 52, 150 of the present invention provide thedishwasher 10 with an additional cleaning zone. Existing solutions forproviding additional cleaning zones have large pressure losses in thespray devices, which results in low exit velocity of the sprayed liquidand decreased cleaning performance. The decreased cleaning performancecan lead to increased cycle times in order to adequately clean utensils.The spray manifolds of the invention, particularly the second and thirdembodiments 52, 150 shown herein, can reduce or even eliminate pressureloss within the manifold, resulting in higher exit velocities of liquidsprayed from the spray manifold, thereby improving cleaning performanceand reducing cycle times. The spray manifolds of the invention,particularly the second and third embodiments 52, 150, accomplish thisby configuring the interior flow paths to lack any sharp transitionsand/or such that the volumetric flow rate requirement of each sprayer54, 152, 154 is met.

The foregoing detailed description of the invention has been presentedfor purposes of illustration and description. It is not intended to beexhaustive nor limit the invention to the precise form disclosed. Manyalternatives, modifications and variations have been discussed above,and others will be apparent to those skilled in the art in light of theabove teaching.

We claim:
 1. A dishwasher comprising: a tub at least partially forming atreating chamber; a dish rack provided within the treating chamber anddefining a utensil zone in which utensils are received for washing; anda spray manifold provided within the treating chamber such that liquidemitted from the spray manifold defines a first spray zone directedtoward the utensil zone, the spray manifold comprising: a first rotatingspray head coupled to an exterior surface of the spray manifold andhaving at least one aperture for emitting liquid; a second rotatingspray head coupled to the exterior surface of the spray manifold andhaving at least one aperture for emitting liquid; a first interior flowpath that supplies liquid to the first rotating spray head; and a secondinterior flow path that supplies liquid to the second rotating sprayhead; wherein the first and second interior flow paths are configured tosupply liquid to the first and second rotating spray heads,respectively, at the same volumetric flow rate.
 2. The dishwasher ofclaim 1, further comprising a spray assembly provided within thetreating chamber and emitting liquid to provide a spray within thetreating chamber that forms a second spray zone directed toward theutensil zone.
 3. The dishwasher of claim 2 wherein the spray assemblycomprises a rotating spray arm having at least one nozzle emittingliquid to form the second spray zone.
 4. The dishwasher of claim 1wherein the first and second interior flow paths have the samecross-sectional area.
 5. The dishwasher of claim 1 wherein the first andsecond rotating spray heads define the first spray zone, and eachrotating spray head emits liquid at the same volumetric flow rate tocreate a consistent cleaning effect across the first spray zone.
 6. Thedishwasher of claim 1 wherein the spray manifold comprises a stationaryspray head in fluid communication with the first interior flow path foremitting liquid.
 7. The dishwasher of claim 6 wherein the stationaryspray head is provided vertically above the first rotating spray head.8. The dishwasher of claim 7 wherein the dish rack comprises an upperedge and the stationary spray head is provided at least partially abovethe upper edge.
 9. The dishwasher of claim 1 wherein the first andsecond rotating spray heads each include a plurality of apertures in aperipheral side surface of the spray head configured to sprayperipherally from the spray head to produce a driving force to rotatethe spray head.
 10. The dishwasher of claim 1 wherein the spray manifoldcomprises at least a first branch and a second branch and wherein thefirst rotating spray head is provided in the first branch and the secondrotating spray head is provided in the second branch.
 11. The dishwasherof claim 10 wherein the first and second branches each include at leastone stationary spray head disposed vertically above the first and secondrotating spray heads, respectively.
 12. The dishwasher of claim 10wherein the first branch includes a third rotating spray head laterallyspaced from the first rotating spray head and the second branch includesa fourth rotating spray head laterally spaced from the second rotatingspray head.
 13. A dishwasher comprising: a tub at least partiallyforming a treating chamber; a dish rack provided within the treatingchamber and defining a utensil zone in which utensils are received forwashing; and a spray manifold having multiple rotating spray heads, eachspray head having at least one aperture through which liquid is emittedto define a first spray zone directed toward the utensil zone, andmultiple liquid flow paths, each flow path corresponding to a rotatingspray head, with each flow path supplying liquid at the same volumetricflow rate to the corresponding rotating spray head.
 14. The dishwasherof claim 13 wherein each of the multiple liquid flow paths have the samecross-sectional area.
 15. The dishwasher of claim 13 wherein therotating spray heads define the first spray zone, and each rotatingspray head emits liquid at the same volumetric flow rate to create aconsistent cleaning effect across the first spray zone.
 16. Thedishwasher of claim 13 wherein the spray manifold further comprisesmultiple branches, each branch defining one of the multiple liquid flowpaths.
 17. The dishwasher of claim 16 wherein each branch includes atleast one rotating spray head and at least one stationary spray head.18. The dishwasher of claim 16 wherein each branch includes: a firstlateral body including a first rotating spray head; and a second lateralbody including a second rotating spray head and a stationary spray head.19. The dishwasher of claim 18 wherein each liquid flow path suppliesliquid to the first and second rotating spray heads in each branch atthe same volumetric flow rate.
 20. The dishwasher of claim 13 whereinthe liquid flow path supplying liquid to the multiple rotating sprayheads directs the liquid in a swirling pattern.